Approximately 1.2 million people in the United States and 14 million worldwide suffer from neurogenic bladder—a condition in which an individual lacks normal bladder functionality due to an underlying brain, spinal cord, or pelvic nerve condition. When the nerves that innervate the bladder and urinary sphincters are compromised, the bladder and urinary sphincter fail to function in a normal way. For example; atonic bladder, overactive bladder, detrusor sphincter dysynergia, poorly compliant bladder and the like. In such cases, patients can have difficulty expelling urine and thus are reliant on intermittent bladder catheterization—including clean catheterization up to 15 times a day as discussed above—to empty the bladder of urine and relieve the pressure within the bladder. The passage of such a catheter can both prevent the bladder from becoming chronically over distended with weakened muscle wall or contracted with a tense and thickened wall. By improving bladder drainage, the risk of bladder and kidney infections can be reduced and harm to the kidney from high pressures urinary storage in the bladder can be prevented.
In a normal bladder, the bladder wall will be compliant, meaning that it will relax or stretch with filling (or increasing volume), thereby keeping the bladder at a low pressure. Accordingly, as used herein, “compliance” relates to the change in volume divided by the change in pressure. With the ensuing increase in urinary volume constrained in the bladder, the pressure within the bladder rises. When the pressure reaches a critically elevated level, such as above 40 cm H2O, transmission of high pressures to the kidneys can occur, thereby potentially resulting in subsequent permanent kidney damage and/or failure that may require a kidney transplant or hemodialysis treatment for the remainder of their lives—a costly expense and grueling treatment that is necessary to control the condition of their failing/failed kidneys, including the electrolyte and fluid imbalances associated with kidney failure.
The current, known procedure utilized by clinicians to monitor the state of patients' bladders and the concomitant changes in bladder pressure with urinary volume readings is called Urodynamic Testing (UDS). This technique involves placing catheters in the bladder and/or rectum, and filling the bladder while measuring the compliance, pressure, and volume in the bladder. Drawbacks of UDS are that it requires an extensive amount of capital equipment, is not readily available in all clinics, is long in duration (a typical test requires 1-2 hours for completion), is expensive (around $4500 for testing and interpretation) and is contingent on factors related to the administration and interpretation of the test by the healthcare team. Another disadvantage is that the test is very invasive for patients, as patients have catheters placed in the bladder and rectum, the bladder is filled with fluid at a set rate while the pressure is continuously monitored, and the patients may be asked to urinate on command in front of the team administering the test. A further disadvantage is that it fails to provide a comprehensive summary of the bladder's condition—UDS only provides a snapshot of a single point in time (i.e. the time of test administration). Since UDS is normally done approximately once a year (though can be performed more or less frequently depending on the severity of the patient's disease), bladder pressure can increase between tests and thus bladder and/or kidney damage can go undetected by both physician and patient for prolonged periods of time. It is not uncommon for physicians to see patients with bladders and kidneys that have ‘deteriorated’ between their visits. This makes the initiation of any intervention for worsening bladder pressure (whether behavioral, medical, or surgery) a reactive intervention, rather than proactive.
There is a need in the art for improved systems, methods, and devices for monitoring bladder health of a patient.